Japanese Castle Explorer
The Japanese Castle Explorer is a beautiful looking map that shows the locations of Japan's most famous (and plenty of lesser known) castles. The map has been featured on Google Maps Mania before but has recently added a couple of new features. The site is now available both in English and Japanese. Wikipedia, photo and video layers have also been added to the map.
The map includes a number of well thought out and handy features. For example each castle, comes with a 'best view' button, which when pressed zooms the map in to the best satelitte view of the castle. The map also comes with a 'random castle' button, a 'region' button (which shows the castles in Japan's different regions) and links to more detailed information on each castle.